[Courses] [Postgresql] Belated chat logs, and this week's chat

[Michelle Murrain]

Hi Folks,

I promised the logs, but I was traveling, and things got away from me. 
Here are the logs from the chat last week.

There will be a chat this week, on Wed. (January 16th) at 9:00 AM (15:00 
UTC/GMT)

This weeks lesson will be forthcoming tomorrow.

Peace,
Michelle
--------------------------------

Jan 08 13:04:07 <Balise>	hello there
Jan 08 13:05:44 <pearlbear>	hi
Jan 08 13:06:14 *	Balise more a tourist than anything
Jan 08 13:06:21 *	Balise quiet and studying thoug
Jan 08 13:06:28 <pearlbear>	just FYI, the transcript of this chat will 
be sent to the list
Jan 08 13:07:14 <pearlbear>	well, I don't have an agenda - this is just 
a place to talk about how the course has been going, and if people have 
any questions, etc.
Jan 08 13:10:28 <pearlbear>	does anyone have any questions or comments 
on anything we've covered so far?
Jan 08 13:13:28 *	zemkat (~zk at z8.mscf.uky.edu) has joined #courses
Jan 08 13:16:16 *	HauntedUnix (haunteduni at goatse.co.uk) has joined #courses
Jan 08 13:16:26 <HauntedUnix>	o/
Jan 08 13:21:42 *	Balise is still skimming through 4 weeks of courses in 
1/2hour so doesn't have any question yet ;)
Jan 08 13:22:52 >chanserv<	op #courses
Jan 08 13:22:52 *	ChanServ gives channel operator status to pearlbear
Jan 08 13:26:14 <zemkat>	same here :D
Jan 08 13:27:45 <Balise>	I HAVE a question :)
Jan 08 13:28:20 <Balise>	how do you define a primary key on several 
columns at once? I'm guessing creating the table without a key and 
adding it?
Jan 08 13:28:45 <pearlbear>	Balise: each table should have only one 
primary key - unless you are talking about having a key be a combination?
Jan 08 13:28:51 <pearlbear>	oh, righ
Jan 08 13:28:54 <Balise>	key as a combination yeah
Jan 08 13:28:57 <pearlbear>	oh, right. Add the constraint later
Jan 08 13:29:37 <Balise>	k
Jan 08 13:30:10 <pearlbear>	I've actually never used combination keys, 
so I don't know the syntax offhand
Jan 08 13:30:18 <zemkat>	could you explain more about outer joins?
Jan 08 13:31:19 <pearlbear>	oh, wait, Balise, you can do it in the 
create table step
Jan 08 13:31:45 <pearlbear>	look at this: 
http://www.postgresql.org/docs/8.2/interactive/sql-createtable.html
Jan 08 13:31:59 <pearlbear>	look at adding constraints in the CREATE 
TABLE command
Jan 08 13:33:06 <Balise>	ah nice :)
Jan 08 13:33:07 <Balise>	thank you
Jan 08 13:33:45 <pearlbear>	so you'd do something like CREATE TABLE foo 
(bar text, bat varchar(3), fizz int PRIMARY KEY bar,bat);
Jan 08 13:34:22 <pearlbear>	zemkat: outer joins ... - they basically 
return rows that don't have data, where inner joins won't
Jan 08 13:36:51 <zemkat>	so in the example in week 5 with the left join, 
if a customer had no orders, then date would be NULL?
Jan 08 13:37:20 <zemkat>	for those rows?
Jan 08 13:37:26 <pearlbear>	right
Jan 08 13:37:32 <zemkat>	gotcha. thanks!
Jan 08 13:37:43 <pearlbear>	sure
Jan 08 13:50:05 *	Petra (~pmautio at cs181193032.pp.htv.fi) has joined #courses
Jan 08 14:05:19 *	akk has quit ("Parting is such sweet sorrow")
Jan 08 14:08:30 <pearlbear>	I'll stick around for a while, but the 
official chat time is over
-- 
Michelle Murrain
Coordinator, Nonprofit Open Source Initiative
http://nosi.net

Skype: pearlbear
AIM: pearlbear0